JP2010020856A - Magnetic head manufacturing method and information storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic recording head manufacturing method that forms reversed trapezoidal main poles of a narrow pattern width. <P>SOLUTION: The magnetic recording head manufacturing method includes steps of: forming, on a base plate, a resist layer having a reversed trapezoidal groove at the end to face the medium; applying first ashing to the resist layer, shrinking the resist layer to reduce the groove dimension in the core width direction, and forming a magnetic material layer in the groove to make the recording magnetic pole. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a magnetic head, and more particularly, to a method for manufacturing a magnetic head having an inverted trapezoidal magnetic pole, and an information storage device including the magnetic head.

  In recent years, the storage capacity of a storage device such as a magnetic disk device tends to increase significantly. Along with this, there has been a demand for further improvement in the recording / reproducing characteristics of the magnetic head as well as the improvement in the recording medium. For example, as a magnetic reproducing head, a magnetoresistive effect reproducing element (hereinafter referred to as “reproducing”) such as a GMR (Giant Magnetoresistivity) element capable of obtaining a high reproducing output, or a TMR (Tunneling Magnetoresistance) element capable of obtaining a higher reproducing sensitivity. Heads using "elements") have been developed. On the other hand, induction heads using electromagnetic induction have been developed as magnetic heads.

  In such a background, in a storage device of a perpendicular recording system, that is, a recording system that uses a combination of a perpendicular magnetic recording medium and a perpendicular magnetic head, in order to narrow the track for the purpose of increasing the recording density, it is necessary to move to an adjacent track It is a problem to prevent the leakage magnetic field of the recording medium and prevent the protrusion recording (side track erase) to the adjacent track. For this problem, a technique for forming the main magnetic pole in an inverted trapezoidal shape is known, and a method for manufacturing a magnetic head having an inverted trapezoidal main pole is also known (Patent Document 1, etc.). ).

JP 2007-200399 A

  An object of the present invention is to provide a method of manufacturing a magnetic head capable of forming an inverted trapezoidal main pole having a narrow pattern width.

  The present invention solves the above-described problems by the solving means described below.

  The method of manufacturing the magnetic head includes a step of forming a resist layer having an inverted trapezoidal groove on a substrate, a step of performing a first ashing process on the resist layer, and a dimension of the groove in the core width direction. It is a requirement to include a step of performing a shrink process on the resist layer and a step of forming a magnetic material layer serving as a magnetic pole in the groove so as to be small.

  According to the present invention, it is possible to form a magnetic head having an inverted trapezoidal main pole with a narrow pattern width.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram (cross-sectional view in the element height direction (X direction in the drawing)) showing a configuration example of a magnetic head 1 manufactured by the magnetic head manufacturing method according to the embodiment of the present invention. FIG. 2 is an explanatory view for explaining steps common to the magnetic head manufacturing method according to the embodiment of the present invention and the magnetic head manufacturing method according to the conventional embodiment. 3 to 4 are explanatory views for explaining the method of manufacturing the magnetic head according to the embodiment of the invention. 5 to 7 are explanatory diagrams for explaining a method of manufacturing a magnetic head according to a conventional embodiment. FIG. 8 is a graph showing a change in the pattern width d of the groove 7 formed in the resist layer 8 in the magnetic head manufacturing method according to the embodiment of the present invention and the magnetic head manufacturing method according to the conventional embodiment. FIG. 9 is a graph showing a change in the inclination angle θ of the groove 7 formed in the resist layer 8 in the magnetic head manufacturing method according to the embodiment of the present invention and the magnetic head manufacturing method according to the conventional embodiment. FIG. 10 is a schematic diagram illustrating an example of an information storage device according to an embodiment of the present invention. The symbol d is used as a generic term for the pattern widths d1 to d8, and the symbol θ is used as a generic term for the inclination angles θ1 to θ8.

A magnetic head 1 according to an embodiment of the present invention is a magnetic head having a recording head unit 3 for writing magnetic information to a magnetic recording medium such as a hard disk.
A magnetic recording medium in which a recording head unit 3 is stacked and a medium facing surface (floating surface) 5 is provided on a surface orthogonal to the element height direction and is configured as a head slider, and then rotated by the medium facing surface 5 Recording is performed by surfacing above.
Hereinafter, a perpendicular magnetic recording type magnetic head will be described as the magnetic head 1. However, it is only an example to the last and is not limited to the said structure.

As shown in FIG. 1, the magnetic head 1 is configured as a composite magnetic head including a reproducing head unit 2 and a recording head unit 3 as one embodiment. The application of the present invention is not limited to the composite magnetic head.
Here, FIG. 1 is shown as a cross-sectional view in a direction perpendicular to the core width direction of the magnetic head 1. Incidentally, the medium facing surface 5 is formed at a predetermined position through a polishing process after the lamination process of each layer is completed.

First, a configuration example of the reproducing head unit 2 will be described. As shown in FIG. 1, a lower shield layer 12 is formed on a wafer substrate 11 serving as a base. Further, the reproducing element 13 is formed on the lower shield layer 12. Here, for example, a magnetoresistive effect element such as a TMR element or a GMR element is used for the reproducing element 13, and various structures can be adopted as the film structure. Reference numeral 31 denotes an insulating layer made of Al ₂ O ₃ or the like.

  Further, the upper shield layer 15 is formed on the reproducing element 13 and the insulating layer 31. Both the upper shield layer 15 and the lower shield layer 12 are configured using a magnetic material (soft magnetic material) such as NiFe.

  Next, a configuration example of the recording head unit 3 will be described. A magnetic separation layer 32 made of an insulating material is formed on the upper shield layer 15. A first return yoke 16 made of a magnetic material is formed on the insulating layer 32.

An insulating layer 33 made of Al ₂ O ₃ or the like is formed on the first return yoke 16, and the first coil 17 is formed on the insulating layer 33 in a plane spiral shape using a conductive material. An insulating layer 34 made of Al ₂ O ₃ or the like is formed so as to cover 17.
Further, the raised layer 18 made of a magnetic material is formed on the insulating layer 34 so that the insulating layer 34 and the upper surface are continuous. A configuration in which the raised layer 18 is not provided is also conceivable.

  In the present embodiment, the laminated structure from the wafer substrate 11 to the layer composed of the insulating layer 34 and the raised layer 18 is referred to as “base” (reference numeral 6 in the figure). However, various configurations can be employed for the substrate, and the above configuration is merely an example.

  A main magnetic pole 19 made of a magnetic material is formed on the insulating layer 34 and the raised layer 18. In the step of forming the main magnetic pole 19 (details will be described later), for example, when forming using a plating process, the plating base layer is first formed and the main magnetic pole 19 is formed thereon. However, the plating base layer can be functionally equated with the main magnetic pole 19 and is not shown for simplification of the drawing (the other plating base layers are also not shown). Incidentally, the main magnetic pole 19 is not limited to a single layer structure, and it is conceivable to adopt a multilayer structure in which different magnetic materials are laminated.

A back gap 22 made of a magnetic material is formed on the rear end side of the main magnetic pole 19, an insulating layer 35 made of Al ₂ O ₃ or the like is formed on the main magnetic pole 19, and a back surface is further formed on the insulating layer 35. A second coil 20 made of a conductive material is formed so as to surround the gap 22. Further, a trailing shield 21 made of a magnetic material is formed above the tip of the main pole 19 with a space (referred to as a trailing gap) from the main pole 19. Further, an insulating layer 36 made of an insulating material such as a resist is formed between the upper and lower layers of the second coil 20, and a second return made of a magnetic material connected to the back gap 22 and the trailing shield 21 is further formed thereon. A yoke 23 is formed.

  Further, a protective layer (not shown) is formed on the second return yoke 23, and the magnetic head 1 is completed as a predetermined laminated structure.

  The magnetic material constituting the first return yoke 16, the raised layer 18, the main magnetic pole 19, the trailing shield 21, the back gap 22, and the second return yoke 23 has a high BS (saturation magnetic flux density) and μ (transparent). It is preferable to use a magnetic material (soft magnetic material) having a low magnetic susceptibility from the viewpoint of improving recording characteristics, and examples thereof include NiFe and CoNiFe.

Then, the manufacturing method of the magnetic head 1 which concerns on this embodiment is demonstrated. The description starts from the formation process of the recording head unit 3 characteristic of the present embodiment.
First, as shown in FIG. 2A, thin films are sequentially laminated on the wafer substrate 11 to form a laminated structure up to a layer constituted by the insulating layer 34 and the raised layer 18, that is, the base 6.

Next, as shown in FIG. 2B, a resist layer 8 having an inverted trapezoidal groove 7 is formed on the base 6. As an example, the resist layer 8 is formed by a known photolithography process.
The shape of the groove 7 is an inclination angle θ1 that is an angle formed by a surface perpendicular to the core width direction (Y direction shown in FIG. 2A, the same applies to FIG. 7 below) and the inclined surface of the groove 7. It forms within the range of about 0-30 [°]. As an example, the width of the opening (upper part of the groove 7 in the figure) in the core width direction is about 100 to 300 [nm], and the width (referred to as “pattern width”) d1 of the bottom part (lower part of the groove 7 in the figure) is The depth (vertical direction in the figure) in the film thickness direction (Z direction shown in FIGS. 1 and 2A, the same applies to FIG. 7) is formed to be about 200 [nm] at about 100 [nm]. To do.

Conventionally, as a subsequent process, a main magnetic pole 19 is formed in the groove 7 of the resist layer 8 as shown in FIG. As an example, the main magnetic pole 19 is formed by a plating process using CoNiFe which is a magnetic material.
In the conventional magnetic head in which the demand for higher recording density was not severe, the pattern width of the main magnetic pole 19, that is, d6 = d1 = 100 [nm] was sufficient. Incidentally, θ6 = θ1.
Moreover, the groove 7 having such a shape (size) was in a range that can be formed by a known photolithography process.

  However, in order to cope with further higher recording density, it is required to form a narrower pattern width, and a desired narrow pattern width (for example, d1 = about 60 to 90 [nm]) only by the photolithography process. ) Can no longer be supported.

Here, it has been considered that the applicant of the present application applies a known shrink processing technique (see Japanese Patent Application Laid-Open No. 2005-44823) in order to narrow the pattern width.
For example, following the step shown in FIG. 2 (b), as shown in FIG. 6 (a), a known shrink agent is applied in the groove 7, and baked at a predetermined temperature and a predetermined time, and then washed with water. As a result, the shrink portion 9 is formed, and the pattern width can be reduced. Note that the pattern width can be controlled by the baking temperature, and as an example, d7 = about 60 to 90 [nm].
However, if this method is applied to the formation of the resist layer 8 having the inverted trapezoidal groove 7, the narrow pattern width can be easily reduced as described above, but the shape of the groove 7 is reversed. The subject which becomes not a trapezoid shape but a rectangular shape arises.
More specifically, with respect to an inclination angle θ1 (see FIG. 2B), which is an angle formed by a surface orthogonal to the core width direction and the inclined surface of the groove 7 before the shrink treatment step is performed. Since the inclination angle θ7 (see FIG. 6A) after the shrink processing step is θ1> θ7, it is formed by the plating process after the ashing step (FIG. 6B). The shape of the main magnetic pole 19 becomes a shape close to a rectangular shape as shown in FIG. That is, regarding the tilt angle, there is a relationship of θ1> θ7≈θ8≈θ9. The pattern width is d9 (= d8) <d1 (see FIG. 8).

  The ashing process shown in FIG. 6B is performed by performing plasma etching (for example, using oxygen gas) on the shrink portion 9 formed in the groove 7 by the shrink process. In the plating process of the process, the soft magnetic material forming the main magnetic pole 19 is performed so as to make it easy to attach to the inside of the groove 7, that is, the surface of the shrink portion 9. Therefore, usually, the ashing process is a process required after the shrink process.

On the other hand, in the manufacturing method according to the present embodiment, the ashing process is performed before the shrink process.
More specifically, after the process shown in FIG. 2B, the ashing process shown in FIG. 3A is performed. The ashing process is different from the ashing process performed after the above-described shrinking process as a matter of course, and by performing the ashing process shown in FIG. Even when the next shrink process is performed (see FIG. 3B), the inclination angle θ2 can be maintained at θ2≈θ1.
As an example, the ashing process is performed by plasma etching using oxygen as a gas for generating plasma, but the present invention is not limited to this.

As a result, it is possible to solve the aforementioned problem that the shape of the groove 7 is changed from an inverted trapezoidal shape to a rectangular shape.
That is, if the shrink process for narrowing the pattern width is performed as shown in FIG. 3B after performing the ashing process (see FIG. 3A), the pattern width d3 = 60. Since it becomes possible to narrow to about 90 [nm] and to maintain the inclination angle θ3≈θ2≈θ1, after that, after undergoing a step (described later) shown in FIG. The main magnetic pole 19 formed by the plating process has a narrow pattern width (d5 = d4 = d3) and a reverse trapezoidal shape having a desired inclination angle θ5 as shown in FIG. 4B. Is possible. In other words, regarding the inclination angle, there is a relationship of θ1≈θ2≈θ3≈θ4≈θ5. FIG. 4B shows a state after the soft magnetic metal material for forming the main magnetic pole 19 is formed in the groove 7 by a plating process and then the resist layer 8 is removed by a lift-off process.
In this way, the main magnetic pole 19 can be formed in an inverted trapezoidal shape having a desired inclination angle θ5, so that side erasure that can occur remarkably when the main magnetic pole becomes rectangular is effective. In addition, it is possible to achieve a high recording density by narrowing the track of the magnetic recording medium by providing a narrow pattern width.

Here, the process shown in FIG. 4A will be described. This step is an ashing treatment step required after the shrink treatment step, as described above.
As an example, the ashing process is performed by plasma etching using oxygen as a gas for generating plasma, but the present invention is not limited to this.

Further, as in the present embodiment, the ashing process shown in FIG. 3A and the ashing process shown in FIG. 4A are performed as plasma etching using the same gas (here, oxygen). As a result, the implementation apparatus can be shared, and an increase in the type of gas used can be suppressed, which is very efficient and enables cost reduction.
However, both ashing processes have completely different purposes, and it is inevitably necessary to optimize the etching conditions in order to be able to be performed by the same apparatus. As an example, the processing time for performing the ashing process shown in FIG. 4A is made shorter than the processing time for performing the ashing process shown in FIG. Both steps can be performed as plasma etching.

  As a post-process shown in FIG. 4B, a laminating process having the above-described film configuration is performed on the main magnetic pole 19 to finally complete the magnetic head 1 having the configuration shown in FIG. .

Here, the effect when the ashing process shown in FIG. 3A, which is characteristic of the present embodiment, is performed is shown in comparison with the case where the process is not performed.
First, FIG. 8 is a graph showing how the pattern width d changes with each step. When the ashing process shown in FIG. 3A is not performed (plotted by a circle in the figure), and in the present embodiment where the ashing process shown in FIG. 3A is performed (a triangular mark in the figure) In both cases, the pattern width can be narrowed to the same extent.
On the other hand, FIG. 8 is a graph showing how the inclination angle θ changes with each step. When the ashing process shown in FIG. 3A is not performed (plotted by a circle in the drawing), the inclination angle θ decreases (θ1 → θ8), that is, the shape of the groove 7 changes from an inverted trapezoidal shape to a rectangular shape. In the case of the present embodiment in which the ashing process shown in FIG. 3A is performed (plotted by a triangular mark in the figure), the inclination angle θ does not decrease ( θ1 → θ3), and the result is that the inverted trapezoidal groove shape is maintained.
From these graphs, it is clear that a characteristic and remarkable effect is achieved in this embodiment that the pattern width can be narrowed while maintaining a desired inclination angle.

Subsequently, an information storage device according to an embodiment of the present invention will be described.
By using the magnetic head 1 having the above configuration to configure a magnetic disk device, an MRAM, or the like, an information storage device that can prevent side erasure and can perform higher-density recording is realized.

  As an example of the information storage device, FIG. 10 shows a configuration of a magnetic disk device 50. The magnetic head 1 is incorporated in a head slider 52 that records information with a magnetic recording medium (magnetic recording disk) 51 and reproduces the information. Further, the head slider 52 is attached to a surface of the head suspension 53 that faces the disk surface, fixes the end of the suspension 53, and is capable of rotating the actuator arm 54 and the suspension 53 and the actuator arm 54. It is configured as a storage device having a circuit that detects an electric signal for reading information recorded on the magnetic recording disk 51 and is electrically connected to the magnetoresistive effect element 13 through an insulated conductive line. As an effect, the magnetic recording disk 51 is driven to rotate, so that the head slider 52 floats from the disk surface, and information is recorded with the magnetic recording disk 51 and information is reproduced.

  The information storage device according to the present embodiment includes a magnetic head having an inverted trapezoidal main pole with a narrow pattern width, and can prevent side erasure and can perform higher-density recording.

  As described above, according to the method of manufacturing a magnetic head according to the present embodiment, it is possible to form an inverted trapezoidal main magnetic pole with a narrow pattern width, and as a result, the problem of side erasure is solved, and more A magnetic head and an information storage device capable of high-density recording are provided.

(Additional remark 1) The process of forming the resist layer which has an inverted trapezoidal groove | channel on a base | substrate,
Performing a first ashing treatment of the resist layer;
Performing a shrink treatment of the resist layer so that the dimension of the groove in the core width direction is reduced;
Forming a magnetic material layer serving as a magnetic pole in the groove.
(Additional remark 2) The said 1st ashing process is a plasma etching process, The manufacturing method of the magnetic head of Additional remark 1 characterized by the above-mentioned.
(Supplementary note 3) The method of manufacturing a magnetic head according to supplementary note 2, wherein the plasma etching process uses oxygen as a gas for generating plasma.
(Supplementary Note 4) In the inverted trapezoidal groove, an angle formed by a surface orthogonal to the upper and lower sides of the trapezoid and an inclined surface of the groove is an angle of 0 degrees to 30 degrees. A method for manufacturing a magnetic head according to claim 1.
(Additional remark 5) The process of forming the magnetic material layer used as a magnetic pole in the said groove | channel is a plating process, The manufacturing method of the magnetic head as described in any one of additional marks 1-4 characterized by the above-mentioned.
(Additional remark 6) Between the process of performing the shrink process of the said resist layer, and the process of forming the magnetic material layer used as a magnetic pole in the said groove | channel,
The method of manufacturing a magnetic head according to any one of appendices 1 to 5, further comprising a step of performing a second ashing process on the resist layer on which the shrink process has been performed.
(Supplementary note 7) The method of manufacturing a magnetic head according to supplementary note 6, wherein the second ashing process is a plasma etching process.
(Additional remark 8) The said plasma etching process uses oxygen as gas which generates plasma, The manufacturing method of the magnetic head of Additional remark 7 characterized by the above-mentioned.
(Supplementary Note 9) The second ashing process and the first ashing process differ only in processing time as an etching condition, and the processing time of the second ashing process is the processing time of the first ashing process. The method of manufacturing a magnetic head according to any one of appendices 6 to 8, wherein the method is shorter.
(Supplementary Note 10) A head slider including a magnetic head manufactured by the magnetic head manufacturing method according to any one of Supplementary Notes 1 to 9, and
A suspension for supporting the head slider;
An end of the suspension is fixed, and an actuator arm that is rotatable,
An information storage device comprising: a circuit electrically connected to the magnetic head through an insulated conductive wire on the suspension and the actuator arm.

It is the schematic which shows the structural example of the magnetic head manufactured by the manufacturing method of the magnetic head which concerns on embodiment of this invention. It is explanatory drawing explaining the process common to the manufacturing method of the magnetic head which concerns on embodiment of this invention, and the manufacturing method of the magnetic head which concerns on the conventional embodiment. It is explanatory drawing for demonstrating the manufacturing method of the magnetic head which concerns on embodiment of this invention. It is explanatory drawing for demonstrating the manufacturing method of the magnetic head which concerns on embodiment of this invention. It is explanatory drawing for demonstrating the manufacturing method of the magnetic head which concerns on the conventional embodiment. It is explanatory drawing for demonstrating the manufacturing method of the magnetic head which concerns on the conventional embodiment. It is explanatory drawing for demonstrating the manufacturing method of the magnetic head which concerns on the conventional embodiment. It is a graph which shows the change of the pattern width of the groove | channel formed in the resist layer in the manufacturing method of the magnetic head which concerns on embodiment of this invention, and the manufacturing method of the magnetic head which concerns on the conventional embodiment. It is a graph which shows the change of the inclination-angle of the groove | channel formed in the resist layer in the manufacturing method of the magnetic head which concerns on embodiment of this invention, and the manufacturing method of the magnetic head which concerns on the conventional embodiment. It is the schematic which shows the example of the information storage device which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic head 2 Playback head part 3 Recording head part 5 Medium facing surface 6 Base | substrate 7 Groove 8 Resist layer 9 Shrink part 11 Wafer substrate 13 Lower shield layer 14 Magnetoresistive effect reproducing element 15 Upper shield layer 16 Lower return yoke 19 Main pole 21 Trailing shield 23 Upper return yoke 50 Information storage device (magnetic disk device)

Claims (7)

Forming a resist layer having an inverted trapezoidal groove on the substrate;
Performing a first ashing treatment of the resist layer;
Performing a shrink treatment of the resist layer so that the dimension of the groove in the core width direction is reduced;
Forming a magnetic material layer serving as a magnetic pole in the groove. The method of manufacturing a magnetic head according to claim 1, wherein the first ashing process is a plasma etching process. 3. The method of manufacturing a magnetic head according to claim 2, wherein the plasma etching process uses oxygen as a gas for generating plasma. 4. The inverted trapezoidal groove has an angle between a plane orthogonal to the upper and lower sides of the trapezoid and an inclined surface of the groove of 0 to 30 degrees. A manufacturing method of the magnetic head according to item. Between the step of performing the shrink treatment of the resist layer and the step of forming a magnetic material layer to be a magnetic pole in the groove,
The method of manufacturing a magnetic head according to claim 1, further comprising a step of performing a second ashing process on the resist layer on which the shrink process has been performed. The second ashing process and the first ashing process differ only in processing time as an etching condition, and the processing time of the second ashing process is shorter than the processing time of the first ashing process. The method of manufacturing a magnetic head according to claim 5. A head slider comprising a magnetic head manufactured by the method of manufacturing a magnetic head according to claim 1;
A suspension for supporting the head slider;
An end of the suspension is fixed, and an actuator arm that is rotatable,
An information storage device comprising: a circuit electrically connected to the magnetic head through an insulated conductive wire on the suspension and the actuator arm.